The present invention relates generally to cortical electrode assemblies for recording and stimulating. Particularly, this invention relates to cortical electrode structures adapted for use with micro-wire arrays and depth electrode structures. More particularly, the invention relates to cortical electrode assemblies and a process for forming electrode assemblies which are versatile and which may incorporate combinations of macro electrodes, micro-wire electrode arrays and depth electrodes.
Cortical and depth electrodes are used for monitoring recordable electrical brain activity or electroencephalograph (EEG) signals when less invasive methods do not provide the electrophysiology data necessary. The electrode recording is performed directly on the surgically exposed brain or inside the brain which may be necessary when the seizure focus is too small and/or too deep within the brain to produce a recordable EEG signal. The electrodes are also used for decoding EEG activity, and for stimulation.
The cortical electrode assemblies of the invention allow medical staff the versatility of joining various electrode devices into a cortical electrode assembly and which may include the use of macro electrode contacts, micro-wire contacts and depth electrodes.
Micro-wire electrodes are cortical electrodes having electrode contacts using the diameter of the wire structure itself as the electrode contact. The remainder of the wire electrode structure is insulated so that the only conductive portion of the micro-wire electrode is the exposed cross section of the wire end which is generally perpendicular to the length of the wire itself. Micro-wire electrodes do not utilize flat disc electrode contacts that a lead wire is crimped, welded or otherwise connected to, for example.
Micro-wires may be of different diameters, for example, ranging from 5 microns to several millimeters. The typical micro-wire diameter may range between 25 microns to 175 microns and may be configured in a grid array having the micro-wires differently spaced center to center from the electrode body. Micro-wire electrode devices have leads extending from the device and which may terminate into various interconnecting structures such as an inline tail, a PCB board, or bare wire leads.
This application provides related subject matter to that of utility patent application U.S. Ser. No. 12/924,657 ('657 Application), filed Oct. 1, 2010 and titled Improved Electrode for Recording and Stimulation and which is incorporated by reference herein. The '657 Application and this Application are assigned to and commonly owned by PMT Corporation.